Automatic spark and valve timing control



' Au 20, 1935. 1 H. L. DUNCAN ,0 7

' AUTOMATIC SPARK AND VALVE TIMING CONTROL Filed May 20, 1929 3 Sheets-Shet 1 k fj n i y I v ll llll' v n f i O 69' f 0 Il I llIll HZ Duncan.

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Patented Aug. 20, 1935 UNITED STAT Herbert .L. "Duncan,

to Lewis P.' T hrelkeld,

signor A: I H 2,011,571 AUTOMATIC SPARK AND VALVE TIMING 4 CONTROL Highland Park, Mich., as!

PATENT OFFICE Detroit, Mich. 1

Application May 20, 1929, Serial No. 364,609 -6 Claims. ,(Cl; 123-90) This invention relates to an improvedmechanism for automatically varying both the ignition and valve timing of an internal combustion I engine in relation to the speed of the motor.

The invention seeks, among other objects, to

provide a mechanism which'will materially increase the flexibility of the engine, will increase the power and speed thereof, will tend to reduce the formation of carbon in the engine cylinders and will, at the same time,'effect a saving in consumption of fuel.

course of the following description. In the drawings:

Figure l is anelevati'on showing the timing gear case andgears of aconventional motor vehicle engine and showing my improved mechanism in position on the engine crank shaft,

the

cover plate of the gear case being removed,

Figure 2 is an elevation showing the arms of the mechanism extended,

Figure 3 is a vertical sectional view on the governor line 3--3 of Figure 2, looking in the direction indicated by the arrows,-

Figure 4 is a vertical 'sectional'view on the line 44 of Figure 3,-l0oking-1n the direction indicated by the arrows, the governor'weights, however, being shown retracted,

Figure 5 is a diagrammatic view showing how the valve timing is advanced by the mechanism,

and

m'sm.

Figure 6 is a diagrammatic view showing how the ignition timing is advanced'by the mecha Referring now more particularly to the draw ings,

the numeral l0 indicates the usual timing gear case of a conventionalinternal combustion engine.

Projecting at their forward ends-into the gear case are the engine crankshaft ll,:the

camshaft l2 and the distributor shaft cam shaft I2 is engine in the customary manner and" the shaft l3 operates the distributor in manner.

' cam shaft. 12 is a gear I4 and meshing provided with the usual cams for operating the intake and exhaust valves of the similarly,

the usual However, it has been 'deemedunnec-- essary' to show this mechanism. Fixedto the with said gear is a gear l5 fixed to the distributor shaft l3,

said gears being of the I As shown in Figure crank invention, I provide a drive gear 18 ably fits the portion 56 of being loose on the shaft. Fixed to the gear usual two to one ratio. V 3, the forward end of theshaft H is provided with stepped portions I l6 and I1 and in accordance with the present" 5 which rotatthe shaft, this gear suitably spacedpoints is a plurality of forwardly I projecting pins I9, any approved number of which may be employed.

Keyed upon the reduced portion I! of the crank shaft in spaced parallel relation to'the gear Wis '21. secured to the shaft by api'n 2|. provided at its inner end with a radial governing collar 20 which is also- This collar is flange 22 and fixed to said flange is a plurality of rearwardly projecting pins 23 equi-distantly spaced circumferentially' of said flange. ent instance I have shown the use of four said pins to accommodate an equal number governor weights 24. However, the number these weights may sirable.

In the presof of of be varied as found most de- As shown in Figure 4, the weights are curved to fit, when retracted, about the periphcry of the "flange 22of the collar 29, and projecting from the inner ends of the weights are arms 25 which are apertured to freely receive the pins 23 so that the weights are thus mounted to rock upon said pins. of the arms are yokes ward end portions of Freely surrounding the reduced portion I! the crank shaft ll to lie between the gear and the Formed on the inner ends 26 which straddle the forthe pins IQ of the gear l8.

of Hi collar 20 is a coil spring 21. As seen in Figure 4 this spring is-provided at its ends with hooks 28 one of which engages the forward end portion of one of the pins l9 of the gear l8 while the other of said hooks engages the rearward end portion of-one of. the' pins-23 of the collar 20. spring will, since Thus, as will be seen, this the collar is fixed to the crank shaft, tend'to counter-rotate the gear l8 for re tracting the governor weights 24 and will normally holdsaidweights-retracted. As will beperceived, the gear l8 and associated parts may be readily embodied in the construction of an engine as originally manufactured or may be readily applied as an attachment to the forward ends of the crank shafts of engines already are use. As is usual, the gears l4 and-I8 are of a two to one ratio. I The spring 21 will, the governor weights weights will hug the flange 22 of the collar at low engine speedsQhold 24' retracted so that said or, at best, will be swung outwardly by centrifugal force comparatively little. Thus, as shown be greatly increased while overheating will be tated by the gear at the left of Figure 6, the ignition will be retarded. Considering one cylinder of the engine utor shaft I3. engine as typical, the time of opening of the intake and exhaust valves of the cylinder, as shown at the right of Figure 5, will be advanced while as shown at the right of Figure 6 the igniti'on'will also be advanced." As will be appreciated, the governor weights will, as the speed of the engine is decreased, be retracted for retarding the valve action as well as-also retarding the ignition. Thus, as will be seen, the mechanism will function to simultaneously advance or retard the valve action and ignitionin direct relation to the speed of the motor. Accordingly, as the speed: of the motor is increased, the fuel gases will be admitted to the cylinders progressively earlier, while the exhaust gases will be likewise permitted to escape progressively earlier, the ignition being timed in step with the valve action. As will be appreciated, the flexibility of the motor will thus prevented. Furthermore, due to the earlier exhaust of the burnt fuel gases, very little if any, back pressure inthe engine cylinders will. be

present with the resu will also be obtained. 7 1

Attention is now directed to the fact that by associating the governor weights 24 with the crank shaft, these weights will tend to counterbalance said shaft. When thespeed of the engine issuddenly accelerated, theweights will of course, due to their inertia, tend toabsorb the shock and similarly when the speed. of the'engine is suddenly checked, the governor weights will tend to absorb the shock Having thus described the invention, I claim:

1. As a means for controlling the timing of theinlet and exhaust valves of an internal combustion engine, wherein the timing is responsive it that an increase in power to the speed of the crank shaft, the combine-: =tion with the crank and cam shafts,,of, speed responsivemeans carried by the crank shaft and operatively connected with the cam shaft, said means including a speed responsive device carried by the crank shaft and bodily movable there- ;,with rotatively in permanent synchronism with, the crank shaft speed of, rotation and addition? ally movable in reaction to such speed to provide the variable speed-responsive action, of the device, and an element forming a part of the cam shaft driving means. and carried by and loose to permit rotation. relativelyto the crank shaft, said elementbe relative to the crank shaft ing operatively connected with, the speed. responsive device to be driventhereby, the opera? 'tive relation between the, device and element being such that the element is shiftedrotatively on its axis by position changes of the device pro vided by speed changes of the crank shaft to therebyehange the timing activity shaft M for advancing the distrib- Considering one cylinder of the j on-thecrank shaft.

of the cam shaft, whereby, the speed responsive-device is of an internal combustion engine, wherein the timing is responsive to the speed of the crank shaft, the combination with the crank, cam and timer shafts, of speed responsive means carried by, the crank shaft and operatively "connected with the cam and timer shafts, said means including a speed responsive device carried by the crank and bodily movable therewith rotatively in,

permanent synchronism with the crank shaft speed of rotation and additionally movable in reaction to such speed to provide the variable speedresponsive action of the device, and an element forming apart of the cam and timer shaft drivingmeansand carried by and loose relative to the crank shaft to permit rotation relatively to "the crank shaft, said element being operati ely connected with the speed responsive device to be driven thereby, the operative relation between the device and element being such that the element is shifted rotatively on its axis by position changes of the device provided by speed changes to thereby change the timing and timer shafts, whereby of the crankshaft activity of the cam the speed responsive from the cam and timer shafts and is directly responsive to the speed of the crank shaft.

3. As a means for controlling the timing of the ignition and the inlet and exhaust. valves of an internal combustion engine, wherein the timing is responsive to-the' speed of the crank shaft, and wherein the valve movements arecontrolled by the cam shaftythe combination with the crank, cam and timer shafts, ofspeed responsive meanscarried by the crank shaft and oper-v atively connected ,withthe cam' andtimer shafts, said means including a centrifugal governor car ried by the crank shaft andbodilvmovable there-3 with rotatively in permanent synchronismwith the crank shaft speed of rotationand additionally movable in reaction to and an element forming a partof, the cam and timer shaft driving means and-car'riedby and loose relative to the crankshaft to permit rotation relatively tothe crank shaft, said element.

being operatively connected with the centrifugal governor to be driven thereby, the operative con-"i nection between the governor and element'-being- 'suchthat the element-is shifted rotativelyon itsaxis by position changes of the crankshaft to thereby change the timing. activity of the cam,-

ignition: and the inlet and exhaust valves of an, internal combustion engine, wherein the timing is responsive to the speed of the crank shaft',- .and

device is positioned remote such speed to provide the variable speed-,responsi-ve -action of the device,

to the speed of the wherein the. valve movements are controlled by' the cam shaft, the combination vwith the crank,

cam and timer shafts, of speed responsive means carried by the. crankshaft and operatively con nected with the cam and timer shafts, said; means including a centrifugal governor carried by the crankshaft-and bodily movable therewith 'rotatively, in permanent synchronism with the crank shaft speed of rotation and additionally movable in reaction to such speed to provide the variable speed-responsive action of thedevice, an'element forming a partof the cam and timer'shaft driving means and carried by and loose relative to the crank shaft to permit rotation relatively to the crank shaft, said element being operatively connected with the centrifugal governor to be driven thereby, the operative connection between the governor and element being such that the element is shifted rotatively on its axis by position changes of the crank shaft to thereby change the timing activity of the cam and timer shafts, whereby the governor is positioned remote from the cam and timer shafts and is directly responsive to the speed of the crank shaft, and a resistance means operatively connecting the governor and element and variable as to power by element shifting movements, said latter meansand the centrifugal force characteristic of the governor cooperating to cushion the advance of the element in presence of rapid increase of speed of the crank shaft and to cause increased responsiveness of the governor to decrease in speed of the crank shaft, whereby vibrations due to speed changes of the crank shaft will be dampened.

5. In an internal combustion engine, the combination of a crank shaft, a cam shaft, a distributor shaft, tappet inlet and exhaust valves actuated by the cam shaft, a distributor actuated by the distributor shaft, a gear fixed to the distributor shaft, a gear fixed to the cam shaft meshing with the distributor gear, said gears being of the usual two to one ratio, a loose gear on the crank shaft meshing with the cam shaft gear, said loose gear being rotative relative to the crank shaft, and a centrifugal governor having to provide bodily movement of the governor in a path concentric with the crank shaft axis and in permanent speed synchronism with the crank shaft, said governor being operativelyconnected to rotate the loose gear independent of the crank shaft by speed-responsive movements of the governor to simultaneouslyvary the timing of the inlet valves, exhaust valves and distributor.

6. In an internal combustion engine, the combination of a crank shaft, a cam shaft, a distributor shaft, inlet and exhaust valves actuated by the cam shaft, a distributor actuated by the distributor shaft, a timing gear case, a gear in the gear case fixed to the distributor shaft, a gear in the gear case fixed to the cam shaft and meshing with the distributor gear, said gears being of the usual two to one ratio, a gear in the gear case loose on the crank shaft and meshing with the cam shaft gear, said loose gear being rotative relative to the crank shaft, and a centrifugal governor in'the gear case having a direct drive connection with the crank shaft to provide bodily movement of thegovernor in a path concentric with the crank shaft axis and in perma nent speed synchronism with'the crank shaft,

said governor being operatively connected to the loose gear and imparting rotary movement to the loose gear independent of the crank shaft by,

speed-responsive movements of the governor to a direct drive connection with the crank shaft simultaneously vary the timing of the inlet valves,

exhaust valves and distributor.

HERBERT L. DUNCAN. [L. 5.] 

